Systems and methods for using registered fluoroscopic images in image-guided surgery

ABSTRACT

A method performed by a computing system comprises receiving a fluoroscopic image of a patient anatomy while a portion of a medical instrument is positioned within the patient anatomy. The fluoroscopic image has a fluoroscopic frame of reference. The portion has a sensed position in an anatomic model frame of reference. The method further comprises identifying the portion in the fluoroscopic image and identifying an extracted position of the portion in the fluoroscopic frame of reference using the identified portion in the fluoroscopic image. The method further comprises registering the fluoroscopic frame of reference to the anatomic model frame of reference based on the sensed position of the portion and the extracted position of the portion.

RELATED APPLICATIONS

This patent application claims priority to and the benefit of the filingdate of U.S. Provisional Patent Application No. 62/294,870, entitled“SYSTEMS AND METHODS FOR USING FLUOROSCOPY TO ASSIST INSTRUMENTNAVIGATION IN IMAGE-GUIDED SURGERY,” filed Feb. 12, 2016, and U.S.Provisional Patent Application No. 62/294,879 entitled “SYSTEMS ANDMETHODS FOR USING REGISTERED FLUOROSCOPIC IMAGES IN IMAGE-GUIDEDSURGERY,” filed Feb. 12, 2016, both of which are hereby incorporated byreference in their entirety.

FIELD

The present disclosure is directed to systems and methods for conductingan image-guided procedure, and more particularly to systems and methodsfor using registered real-time fluoroscopic images and prior-timeanatomic images during an image-guided procedure.

BACKGROUND

Minimally invasive medical techniques are intended to reduce the amountof tissue that is damaged during medical procedures, thereby reducingpatient recovery time, discomfort, and harmful side effects. Suchminimally invasive techniques may be performed through natural orificesin a patient anatomy or through one or more surgical incisions. Throughthese natural orifices or incisions clinicians may insert minimallyinvasive medical instruments (including surgical, diagnostic,therapeutic, or biopsy instruments) to reach a target tissue location.To assist with reaching the target tissue location, the location andmovement of the medical instruments may be correlated with pre-operativeor prior intra-operative static images of the patient anatomy. With theimage-guided instruments correlated to the images, the instruments maynavigate natural or surgically created passageways in anatomic systemssuch as the lungs, the colon, the intestines, the kidneys, the heart,the circulatory system, or the like. Traditionally the pre-operative orintra-operative images of the patient anatomy are detailed, oftenthree-dimensional, images. However, they are static prior-timerepresentations of the patient anatomy. Fluoroscopy is an imagingmodality that provides real-time images of the patient anatomy includingany radiopaque instruments in use during a medical procedure on thepatient anatomy. Fluoroscopic images, however, may not capture highquality images of certain types of tissues. Systems and methods areneeded to register real-time fluoroscopic and prior-time static imagesto provide enhanced navigation information for performing image-guidedsurgery.

SUMMARY

The embodiments of the invention are summarized by the claims thatfollow the description.

In one embodiment, method performed by a computing system comprisesreceiving a fluoroscopic image of a patient anatomy while a portion of amedical instrument is positioned within the patient anatomy. Thefluoroscopic image has a fluoroscopic frame of reference. This portionmay be referred to as an indicator portion, and the portion may compriseany length of the medical instrument, including, by way of non-limitingexample, a proximal section, a midsection, a distal section, and/or adistal end of the medical instrument. The portion has a sensed orotherwise known position in an anatomic model frame of reference. Themethod further comprises identifying the portion position in thefluoroscopic image and identifying an extracted position of the portionin the fluoroscopic frame of reference using the portion position in thefluoroscopic image. The method further comprises registering thefluoroscopic frame of reference to the anatomic model frame of referencebased on the sensed position of the portion and the extracted positionof the portion.

In another embodiment, a method performed by a computing systemcomprises identifying a set of positions of plurality of anatomiclandmarks, the plurality of anatomic landmarks rendered in an anatomicmodel of passageways of a patient anatomy in a model frame of referenceand receiving fluoroscopic image data of the patient anatomy while aportion of a medical instrument traverses the plurality of anatomiclandmarks in the passageways of the patient anatomy. The fluoroscopicimage data has a fluoroscopic frame of reference. The method furthercomprises identifying a set of portion positions at the plurality ofanatomic landmarks in the fluoroscopic frame of reference andregistering the set of positions of plurality of anatomic landmarks inthe model frame of reference and the set of portion positions in thefluoroscopic frame of reference to a common frame of reference.

In another embodiment, a method performed by a computing systemcomprises receiving a set of model points for an anatomic model ofpassageways of a patient anatomy in a model frame of reference andreceiving fluoroscopic image data of the patient anatomy while anindicator portion of a medical instrument traverses the passageways ofthe patient anatomy. The fluoroscopic image data has a fluoroscopicframe of reference. The method further comprises identifying from thefluoroscopic image data, a set of indicator portion position points inthe fluoroscopic frame of reference and matching each indicator portionposition point to a model point in the set of model points to generate aset of matches. The method further comprises registering the model frameof reference to the fluoroscopic frame of reference based on the set ofmatches.

In another embodiment, a computer-assisted medical system comprises afluoroscopic imager having a plane of orientation within a surgicalcoordinate space, and one or more processors. The one or more processorsare configured to perform a method including: receiving a fluoroscopicimage of a patient anatomy while a portion of a medical instrument ispositioned at a location within the patient anatomy, the fluoroscopicimage having a plane of orientation. The method also comprises receivinga command to drive motion of the portion of the medical instrument,constraining actuation of the portion such that actuated movement of theportion is constrained to the plane of orientation of the fluoroscopicimage, and driving the motion of the portion with the constrainedactuation. In one aspect, system further comprises receiving sensorinformation from the medical instrument while driving the motion of theportion with the constrained actuation, recognizing movement of theportion out of the plane of orientation of the fluoroscopic image fromthe received sensor information, and receiving a signal to adjust theportion into the plane of orientation of the fluoroscopic image.

In another embodiment, a method performed by a computing systemcomprises receiving an anatomic model of a patient anatomy, wherein anarea of interest is identified in the anatomic model. The method furthercomprises receiving shape sensor data from an instrument shape sensor ofan instrument positioned within the patient anatomy and registered tothe anatomic model, and determining a fluoroscopic image plane fordisplay based on the received shape sensor data and the area ofinterest.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory innature and are intended to provide an understanding of the presentdisclosure without limiting the scope of the present disclosure. In thatregard, additional aspects, features, and advantages of the presentdisclosure will be apparent to one skilled in the art from the followingdetailed description.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isemphasized that, in accordance with the standard practice in theindustry, various features are not drawn to scale. In fact, thedimensions of the various features may be arbitrarily increased orreduced for clarity of discussion. In addition, the present disclosuremay repeat reference numerals and/or letters in the various examples.This repetition is for the purpose of simplicity and clarity and doesnot in itself dictate a relationship between the various embodimentsand/or configurations discussed.

FIG. 1 is a teleoperated medical system, in accordance with embodimentsof the present disclosure.

FIG. 2A illustrates a medical instrument system utilizing aspects of thepresent disclosure.

FIG. 2B illustrates a distal end of the medical instrument system ofFIG. 2A with an extended medical tool, in accordance with embodiments ofthe present disclosure.

FIG. 3 illustrates the distal end of the medical instrument system ofFIG. 2A positioned within a human lung.

FIG. 4 is a flowchart illustrating a method used to provide guidance inan image-guided surgical procedure according to an embodiment of thepresent disclosure.

FIG. 5 is a side view of a surgical coordinate space including a medicalinstrument and a fluoroscopic imaging system according to an embodimentof the present disclosure.

FIG. 6 illustrates a flowchart of an image-guided surgical procedureaccording to an embodiment of the present disclosure.

FIG. 7 illustrates a flowchart of an image-guided surgical procedureaccording to another embodiment of the present disclosure.

FIG. 8 illustrates a flowchart of a portion of an image-guided surgicalprocedure according to another embodiment of the present disclosure.

FIGS. 9A, 9B, and 9C illustrate fluoroscopic images for determining aninstrument portion position in a fluoroscopic frame of reference.

FIG. 10 is a display device on which is displayed registeredside-by-side fluoroscopic and anatomic model images according to anembodiment of the present disclosure.

FIG. 11 is a display device on which is displayed an anatomic modelimage registered and overlaid on a fluoroscopic image according to anembodiment of the present disclosure.

FIG. 12 illustrates a correlation table describing correlated anatomiclandmarks between fluoroscopic and anatomic frames of reference.

FIGS. 13A and 13B illustrate segmentation of fluoroscopic images.

FIG. 14 illustrates a flowchart of a portion of an image-guided surgicalprocedure according to another embodiment of the present disclosure.

FIG. 15 illustrates a method of determining a preferred fluoroscopicplane of view.

FIG. 16 illustrates a method for driving a medical instrument undertwo-dimensional fluoroscopic guidance.

DETAILED DESCRIPTION

In the following detailed description of the aspects of the invention,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. However, it will be obviousto one skilled in the art that the embodiments of this disclosure may bepracticed without these specific details. In other instances well knownmethods, procedures, components, and circuits have not been described indetail so as not to unnecessarily obscure aspects of the embodiments ofthe invention. And, to avoid needless descriptive repetition, one ormore components or actions described in accordance with one illustrativeembodiment can be used or omitted as applicable from other illustrativeembodiments.

The embodiments below will describe various instruments and portions ofinstruments in terms of their state in three-dimensional space. As usedherein, the term “position” refers to the location of an object or aportion of an object in a three-dimensional space (e.g., three degreesof translational freedom along Cartesian X, Y, Z coordinates). As usedherein, the term “orientation” refers to the rotational placement of anobject or a portion of an object (three degrees of rotationalfreedom—e.g., roll, pitch, and yaw). As used herein, the term “pose”refers to the position of an object or a portion of an object in atleast one degree of translational freedom and to the orientation of thatobject or portion of the object in at least one degree of rotationalfreedom (up to six total degrees of freedom). As used herein, the term“shape” refers to a set of poses, positions, or orientations measuredalong an object.

Referring to FIG. 1 of the drawings, a teleoperated medical system foruse in, for example, surgical, diagnostic, therapeutic, or biopsyprocedures, is generally indicated as teleoperated medical system 100.As shown in FIG. 1, the teleoperated system 100 generally includes ateleoperational manipulator assembly 102 for operating a medicalinstrument system 104 in performing various procedures on the patient P.The teleoperational manipulator assembly 102 may also be referred to asteleoperational assembly 102 or manipulator assembly 102. The medicalinstrument system 104 may also be referred to as medical instrument 104.The manipulator assembly 102 is mounted to or near an operating table O.An operator input system 106 (also called “master assembly 106”) allowsthe clinician or surgeon S to view the interventional site and tocontrol the manipulator assembly 102.

The operator input system 106 may be located at a surgeon's consolewhich is usually located in the same room as operating table O. However,it should be understood that the surgeon S can be located in a differentroom or a completely different building from the patient P. The operatorinput assembly 106 generally includes one or more control devices forcontrolling one or more manipulator assemblies 102. The control devicesmay include any number of a variety of input devices, such as joysticks,trackballs, data gloves, trigger-guns, hand-operated controllers, voicerecognition devices, body motion or presence sensors, or the like. Insome embodiments, the control devices will be provided with the samedegrees of freedom as the associated medical instruments 104 to providethe surgeon with telepresence, or the perception that the controldevices are integral with the instruments 104 so that the surgeon has astrong sense of directly controlling instruments 104. In otherembodiments, the control devices may have more or fewer degrees offreedom than the associated medical instruments 104 and still providethe surgeon with telepresence. In some embodiments, the control devicesare manual input devices which move with six degrees of freedom, andwhich may also include an actuatable handle for actuating instruments(for example, for closing grasping jaws, applying an electricalpotential to an electrode, delivering a medicinal treatment, or thelike).

The teleoperational assembly 102 supports the medical instrument system104 and may include a kinematic structure of one or more non-servocontrolled links (e.g., one or more links that may be manuallypositioned and locked in place, generally referred to as a set-upstructure) and a teleoperational manipulator. The teleoperationalassembly 102 includes a plurality of actuators or motors that driveinputs on the medical instrument system 104 in response to commands fromthe control system (e.g., a control system 112). The motors includedrive systems that when coupled to the medical instrument system 104 mayadvance the medical instrument into a naturally or surgically createdanatomic orifice. Other motorized drive systems may move the distal endof the medical instrument in multiple degrees of freedom, which mayinclude three degrees of linear motion (e.g., linear motion along the X,Y, Z Cartesian axes) and in three degrees of rotational motion (e.g.,rotation about the X, Y, Z Cartesian axes). Additionally, the motors canbe used to actuate an articulable end effector of the instrument forgrasping tissue in the jaws of a biopsy device or the like. Motorposition sensors such as resolvers, encoders, potentiometers, and othermechanisms may provide sensor data to the teleoperational assemblydescribing the rotation and orientation of the motor shafts. Thisposition sensor data may be used to determine motion of the objectsmanipulated by the motors.

The teleoperational medical system 100 also includes a sensor system 108with one or more sub-systems for receiving information about theinstruments of the teleoperational assembly. Such sub-systems mayinclude a position/location sensor system (e.g., an electromagnetic (EM)sensor system); a shape sensor system for determining the position,orientation, speed, velocity, pose, and/or shape of the catheter tipand/or of one or more segments along a flexible body of medicalinstrument system 104; and/or a visualization system for capturingimages from the distal end of the catheter system.

The visualization system (e.g., visualization system 231 of FIG. 2A) mayinclude a viewing scope assembly that records a concurrent or real-timeimage of the surgical site and provides the image to the clinician orsurgeon S. The concurrent image may be, for example, a two or threedimensional image captured by an endoscope positioned within thesurgical site. In this embodiment, the visualization system includesendoscopic components that may be integrally or removably coupled to themedical instrument 104. However in alternative embodiments, a separateendoscope, attached to a separate manipulator assembly may be used withthe medical instrument to image the surgical site. The visualizationsystem may be implemented as hardware, firmware, software or acombination thereof which interact with or are otherwise executed by oneor more computer processors, which may include the processors of acontrol system 112 (described below). The processors of the controlsystem 112 may execute instructions comprising instruction correspondingto processes disclosed herein.

The teleoperational medical system 100 also includes a display system110 (also “display 110”) for displaying an image or representation ofthe surgical site and medical instrument system(s) 104 generated bysub-systems of the sensor system 108. The display system 110 and theoperator input system 106 may be oriented so the operator can controlthe medical instrument system 104 and the operator input system 106 withthe perception of telepresence.

The display system 110 may also display an image of the surgical siteand medical instruments captured by the visualization system. Thedisplay system 110 and the control devices may be oriented such that therelative positions of the imaging device in the scope assembly and themedical instruments are similar to the relative positions of thesurgeon's eyes and hands so the operator can manipulate the medicalinstrument 104 and the hand control as if viewing the workspace insubstantially true presence. By true presence, it is meant that thepresentation of an image is a true perspective image simulating theviewpoint of an operator that is physically manipulating the instrument104.

Alternatively or additionally, the display system 110 may present imagesof the surgical site recorded pre-operatively or intra-operatively usingimage data from imaging technology such as, computed tomography (CT),magnetic resonance imaging (MRI), fluoroscopy, thermography, ultrasound,optical coherence tomography (OCT), thermal imaging, impedance imaging,laser imaging, or nanotube X-ray imaging. The pre-operative orintra-operative image data may be presented as two-dimensional,three-dimensional, or four-dimensional (including e.g., time based orvelocity based information) images or as images from models created fromthe pre-operative or intra-operative image data sets.

In some embodiments often for purposes of imaged guided surgicalprocedures, the display system 110 may display a virtual navigationalimage in which the actual location of the medical instrument 104 isregistered (i.e., dynamically referenced) with the preoperative orconcurrent images/model to present the clinician or surgeon S with avirtual image of the internal surgical site from the viewpoint of thelocation of the tip of the instrument 104. An image of the tip of theinstrument 104 or other graphical or alphanumeric indicators may besuperimposed on the virtual image to assist the surgeon controlling themedical instrument. Alternatively, the instrument 104 may not be visiblein the virtual image.

In other embodiments, the display system 110 may display a virtualnavigational image in which the actual location of the medicalinstrument is registered with preoperative or concurrent images topresent the clinician or surgeon S with a virtual image of medicalinstrument within the surgical site from an external viewpoint. An imageof a portion of the medical instrument or other graphical oralphanumeric indicators may be superimposed on the virtual image toassist the surgeon controlling the instrument 104.

The teleoperational medical system 100 also includes a control system112. The control system 112 includes at least one memory and at leastone computer processor (not shown), and typically a plurality ofprocessors, for effecting control between the medical instrument system104, the operator input system 106, the sensor system 108, and thedisplay system 110. The control system 112 also includes programmedinstructions (e.g., a computer-readable medium storing the instructions)to implement some or all of the methods described in accordance withaspects disclosed herein, including instructions for providingregistered images to the display system 110. While control system 112 isshown as a single block in the simplified schematic of FIG. 1, thesystem may include two or more data processing circuits with one portionof the processing optionally being performed on or adjacent theteleoperational assembly 102, another portion of the processing beingperformed at the operator input system 106, and the like. Any of a widevariety of centralized or distributed data processing architectures maybe employed. Similarly, the programmed instructions may be implementedas a number of separate programs or subroutines, or they may beintegrated into a number of other aspects of the teleoperational systemsdescribed herein. In one embodiment, control system 112 supportswireless communication protocols such as Bluetooth, IrDA, HomeRF, IEEE802.11, DECT, and Wireless Telemetry.

In some embodiments, control system 112 may include one or more servocontrollers that receive force and/or torque feedback from the medicalinstrument system 104. Responsive to the feedback, the servo controllerstransmit signals to the operator input system 106. The servocontroller(s) may also transmit signals instructing teleoperationalassembly 102 to move the medical instrument system(s) 104 which extendinto an internal surgical site within the patient body via openings inthe body. Any suitable conventional or specialized servo controller maybe used. A servo controller may be separate from, or integrated with,teleoperational assembly 102. In some embodiments, the servo controllerand teleoperational assembly are provided as part of a teleoperationalarm cart positioned adjacent to the patient's body.

The control system 112 may further include a virtual visualizationsystem to provide navigation assistance to the medical instrumentsystem(s) 104 when used in an image-guided surgical procedure. Virtualnavigation using the virtual visualization system is based uponreference to the acquired preoperative or intraoperative dataset of theanatomic passageways. More specifically, the virtual visualizationsystem processes images of the surgical site imaged using imagingtechnology such as computerized tomography (CT), magnetic resonanceimaging (MRI), fluoroscopy, thermography, ultrasound, optical coherencetomography (OCT), thermal imaging, impedance imaging, laser imaging,nanotube X-ray imaging, or the like. Software alone or in combinationwith manual input is used to convert the recorded images into segmentedtwo dimensional or three dimensional composite representation of apartial or an entire anatomic organ or anatomic region. An image dataset is associated with the composite representation. The compositerepresentation and the image data set describe the various locations andshapes of the passageways and their connectivity. The images used togenerate the composite representation may be recorded preoperatively orintra-operatively at a prior time during a clinical procedure. In analternative embodiment, a virtual visualization system may use standardrepresentations (i.e., not patient specific) or hybrids of a standardrepresentation and patient specific data. The composite representationand any virtual images generated by the composite representation mayrepresent the static posture of a deformable anatomic region during oneor more phases of motion (e.g., during an inspiration/expiration cycleof a lung).

During a virtual navigation procedure, the sensor system 108 may be usedto compute an approximate location of the instrument with respect to thepatient anatomy. The location can be used to produce both macro-level(external) tracking images of the patient anatomy and virtual internalimages of the patient anatomy. Various systems for using electromagnetic(EM) sensor, fiber optic sensors, or other sensors to register anddisplay a medical implement together with preoperatively recordedsurgical images, such as those from a virtual visualization system, areknown. For example U.S. patent application Ser. No. 13/107,562 (filedMay 13, 2011) (disclosing “Medical System Providing Dynamic Registrationof a Model of an Anatomic Structure for Image-Guided Surgery”) which isincorporated by reference herein in its entirety, discloses one suchsystem.

The teleoperational medical system 100 may further include optionaloperation and support systems (not shown) such as illumination systems,steering control systems, irrigation systems, and/or suction systems. Inalternative embodiments, the teleoperational system may include morethan one teleoperational assembly and/or more than one operator inputsystem. The exact number of manipulator assemblies will depend on thesurgical procedure and the space constraints within the operating room,among other factors. The operator input systems may be collocated orthey may be positioned in separate locations. Multiple operator inputsystems allow more than one operator to control one or more manipulatorassemblies in various combinations.

FIG. 2A illustrates a medical instrument system 200 system (also“medical instrument 200” or “instrument system 200”), which may be usedas the medical instrument system 104 in an image-guided medicalprocedure performed with teleoperational medical system 100.Alternatively, the medical instrument system 200 may be used fornon-teleoperational exploratory procedures or in procedures involvingtraditional manually operated medical instruments, such as endoscopy.Additionally or alternatively the medical instrument system 200 may beused to gather (i.e., measure) a set of data points corresponding tolocations with patient anatomic passageways.

The instrument system 200 includes a catheter system 202 (also “catheter202”) coupled to an instrument body 204 that, when used to housecomponents, may be referred to as “housing 204”. The catheter system 202includes an elongated flexible catheter body 216 having a proximal end217 and a distal end 218 (which may be called “tip portion 218” when itis the tip portion of the catheter body 216″). In one embodiment, theflexible body 216 has an approximately 3 mm outer diameter. Otherflexible body outer diameters may be larger or smaller. The cathetersystem 202 may optionally include a shape sensor system 222 (also “shapesensor 222”) for determining the position, orientation, speed, velocity,pose, and/or shape of the catheter tip at distal end 218 and/or of oneor more segments 224 along the catheter body 216. The entire length ofthe catheter body 216, between the distal end 218 and the proximal end217, may be effectively divided into the segments 224. If the instrumentsystem 200 is a medical instrument 104 of a teleoperational medicalsystem 100, the shape sensor system 222 may be a component of the sensorsystem 108. If the instrument system 200 is manually operated orotherwise used for non-teleoperational procedures, the shape sensorsystem 222 may be coupled to a tracking system 230 that interrogates theshape sensor and processes the received shape data.

The shape sensor system 222 may include an optical fiber aligned withthe flexible catheter body 216 (e.g., provided within an interiorchannel (not shown) or mounted externally). In one embodiment, theoptical fiber has a diameter of approximately 200 μm. In otherembodiments, the dimensions may be larger or smaller. The optical fiberof the shape sensor system 222 forms a fiber optic bend sensor fordetermining the shape of the catheter system 202. In one alternative,optical fibers including Fiber Bragg Gratings (FBGs) are used to providestrain measurements in structures in one or more dimensions. Varioussystems and methods for monitoring the shape and relative position of anoptical fiber in three dimensions are described in U.S. patentapplication Ser. No. 11/180,389 (filed Jul. 13, 2005) (disclosing “Fiberoptic position and shape sensing device and method relating thereto”);U.S. patent application Ser. No. 12/047,056 (filed on Jul. 16, 2004)(disclosing “Fiber-optic shape and relative position sensing”); and U.S.Pat. No. 6,389,187 (filed on Jun. 17, 1998) (disclosing “Optical FibreBend Sensor”), which are all incorporated by reference herein in theirentireties. Sensors in alternative embodiments may employ other suitablestrain sensing techniques, such as Rayleigh scattering, Ramanscattering, Brillouin scattering, and Fluorescence scattering. In otheralternative embodiments, the shape of the catheter may be determinedusing other techniques. For example, the history of the catheter'sdistal tip pose can be used to reconstruct the shape of the device overthe interval of time. As another example, historical pose, position, ororientation data may be stored for a known point of an instrument systemalong a cycle of alternating motion, such as breathing. This stored datamay be used to develop shape information about the catheter.Alternatively, a series of positional sensors, such as electromagnetic(EM) sensors, positioned along the catheter can be used for shapesensing. Alternatively, a history of data from a positional sensor, suchas an EM sensor, on the instrument system during a procedure may be usedto represent the shape of the instrument, particularly if an anatomicpassageway is generally static. Alternatively, a wireless device withposition or orientation controlled by an external magnetic field may beused for shape sensing. The history of the wireless device's positionmay be used to determine a shape for the navigated passageways.

The medical instrument system may, optionally, include a position sensorsystem 220. The position sensor system 220 may be a component of an EMsensor system with the sensor system 220 including one or moreconductive coils that may be subjected to an externally generatedelectromagnetic field. In such an embodiment, each coil of the EM sensorsystem comprising the position sensor system 220 then produces aninduced electrical signal having characteristics that depend on theposition and orientation of the coil relative to the externallygenerated electromagnetic field. In one embodiment, the EM sensor systemmay be configured and positioned to measure six degrees of freedom,e.g., three position coordinates X, Y, Z and three orientation anglesindicating pitch, yaw, and roll of a base point or five degrees offreedom, e.g., three position coordinates X, Y, Z and two orientationangles indicating pitch and yaw of a base point. Further description ofan EM sensor system is provided in U.S. Pat. No. 6,380,732 (filed Aug.11, 1999) (disclosing “Six-Degree of Freedom Tracking System Having aPassive Transponder on the Object Being Tracked”), which is incorporatedby reference herein in its entirety. In some embodiments, the shapesensor may also function as the position sensor because the shape of thesensor together with information about the location of the base of theshape sensor (in the fixed coordinate system of the patient) allows thelocation of various points along the shape sensor, including the distaltip, to be calculated.

A tracking system 230 may include the position sensor system 220 and theshape sensor system 222 for determining the position, orientation,speed, pose, and/or shape of the distal end 218 and of one or moresegments 224 along the instrument system 200. The tracking system 230may be implemented as hardware, firmware, software or a combinationthereof which interact with or are otherwise executed by one or morecomputer processors, which may include the processors of a controlsystem 116.

The flexible catheter body 216 includes a channel 221 (See FIG. 2B)sized and shaped to receive a medical instrument 226. Medicalinstruments may include, for example, image capture probes, biopsyinstruments, laser ablation fibers, or other surgical, diagnostic, ortherapeutic tools. Medical tools may include end effectors having asingle working member such as a scalpel, a blunt blade, an opticalfiber, or an electrode. Other end effectors may include, for example,forceps, graspers, scissors, or clip appliers. Examples of electricallyactivated end effectors include electrosurgical electrodes, transducers,sensors, and the like.

In various embodiments, the medical instrument(s) 226 may be an imagecapture probe that includes a distal portion with a stereoscopic ormonoscopic camera at or near the distal end 218 of the flexible catheterbody 216 for capturing images (including video images) that areprocessed by a visualization system 231 for display. The image captureprobe may include a cable coupled to the camera for transmitting thecaptured image data. Alternatively, the image capture instrument may bea fiber-optic bundle, such as a fiberscope, that couples to thevisualization system. The image capture instrument may be single ormulti-spectral, for example capturing image data in one or more of thevisible, infrared, or ultraviolet spectrums.

In various embodiments, the medical instrument 226 is a biopsyinstrument used to remove sample tissue or a sampling of cells from atarget anatomic location. The instrument 226 may be advanced from theopening of the channel 221 to perform the procedure and then retractedback into the channel when the procedure is complete. The medicalinstrument 226 may be removed from the proximal end 217 of the catheterflexible body or from another optional instrument port (not shown) alongthe flexible body.

The medical instrument 226 may house cables, linkages, or otheractuation controls (not shown) that extend between the proximal anddistal ends of the instrument to controllably bend the distal end of theinstrument. Steerable instruments are described in detail in U.S. Pat.No. 7,316,681 (filed on Oct. 4, 2005) (disclosing “Articulated SurgicalInstrument for Performing Minimally Invasive Surgery with EnhancedDexterity and Sensitivity”) and U.S. patent application Ser. No.12/286,644 (filed Sep. 30, 2008) (disclosing “Passive Preload andCapstan Drive for Surgical Instruments”), which are incorporated byreference herein in their entireties.

The flexible catheter body 216 may also houses cables, linkages, orother steering controls (not shown) that extend between the housing 204and the distal end 218 to controllably bend the distal end 218 as shown,for example, by the broken dashed line depictions 219 of the distal end.Steerable catheters are described in detail in U.S. patent applicationSer. No. 13/274,208 (filed Oct. 14, 2011) (disclosing “Catheter withRemovable Vision Probe”), which is incorporated by reference herein inits entirety. In embodiments in which the instrument system 200 isactuated by a teleoperational assembly, the housing 204 may includedrive inputs that removably couple to and receive power from motorizeddrive elements of the teleoperational assembly. In embodiments in whichthe instrument system 200 is manually operated, the housing 204 mayinclude gripping features, manual actuators, or other components formanually controlling the motion of the instrument system. The cathetersystem may be steerable or, alternatively, the system may benon-steerable with no integrated mechanism for operator control of theinstrument bending. Also or alternatively, one or more lumens, throughwhich medical instruments can be deployed and used at a target surgicallocation, are defined in the walls of the flexible body 216.

In various embodiments, the medical instrument system 200 may include aflexible bronchial instrument, such as a bronchoscope or bronchialcatheter, for use in examination, diagnosis, biopsy, or treatment of alung. The instrument system 200 is also suited for navigation andtreatment of other tissues, via natural or surgically created connectedpassageways, in any of a variety of anatomic systems, including thecolon, the intestines, the kidneys, the brain, the heart, thecirculatory system, and the like.

The information from the tracking system 230 may be sent to a navigationsystem 232 where it is combined with information from the visualizationsystem 231 and/or the preoperatively obtained models to provide thesurgeon or other operator with real-time position information on thedisplay system 110 for use in the control of the instrument system 200.The control system 116 may utilize the position information as feedbackfor positioning the instrument system 200. Various systems for usingfiber optic sensors to register and display a surgical instrument withsurgical images are provided in U.S. patent application Ser. No.13/107,562, filed May 13, 2011, disclosing, “Medical System ProvidingDynamic Registration of a Model of an Anatomic Structure forImage-Guided Surgery,” which is incorporated by reference herein in itsentirety.

In the embodiment of FIG. 2A, the instrument system 200 is teleoperatedwithin the teleoperational medical system 100. In an alternativeembodiment, the teleoperational assembly 102 may be replaced by directoperator control. In the direct operation alternative, various handlesand operator interfaces may be included for hand-held operation of theinstrument.

In alternative embodiments, the teleoperated system may include morethan one slave manipulator assembly and/or more than one masterassembly. The exact number of manipulator assemblies will depend on themedical procedure and the space constraints within the operating room,among other factors. The master assemblies may be collocated, or theymay be positioned in separate locations. Multiple master assembliesallow more than one operator to control one or more slave manipulatorassemblies in various combinations.

FIG. 3 illustrates the catheter system 202 positioned within an anatomicpassageway of a patient anatomy. In this embodiment, the anatomicpassageway is an airway of human lungs 201. In alternative embodiments,the catheter system 202 may be used in other passageways of an anatomy.

FIG. 4 is a flowchart illustrating a general method 300 for use in animage-guided surgical procedure. Although various provided examplesdescribe the use of procedures performed within the anatomy, inalternative embodiments, the apparatus and methods of this disclosureneed not be used within the anatomy but rather may also be used outsideof the patient anatomy. At a process 302, prior image data, includingpre-operative or intra-operative image data, is obtained from imagingtechnology such as, computed tomography (CT), magnetic resonance imaging(MM), thermography, ultrasound, optical coherence tomography (OCT),thermal imaging, impedance imaging, laser imaging, or nanotube X-rayimaging. The pre-operative or intra-operative image data may correspondto two-dimensional, three-dimensional, or four-dimensional (includinge.g., time based or velocity based information) images. For example, theimage data may represent the human lungs 201 of FIG. 3.

At a process 304, computer software alone or in combination with manualinput is used to convert the recorded images into a segmentedtwo-dimensional or three-dimensional composite representation or modelof a partial or an entire anatomic organ or anatomic region. Thecomposite representation and the image data set describe the variouslocations and shapes of the passageways and their connectivity. Morespecifically, during the segmentation process the images are partitionedinto segments or elements (e.g., pixels or voxels) that share certaincharacteristics or computed properties such as color, density,intensity, and texture. This segmentation process results in a two- orthree-dimensional reconstruction that forms a model of the targetanatomy or anatomic model based on the obtained image. To represent themodel, the segmentation process may delineate sets of voxelsrepresenting the target anatomy and then apply a function, such asmarching cube function, to generate a 3D surface that encloses thevoxels. The model may be made by generating a mesh, volume, or voxelmap. Additionally or alternatively, the model may include a centerlinemodel that includes a set of interconnected line segments or pointsextending through the centers of the modeled passageways. Where themodel includes a centerline model including a set of interconnected linesegments, those line segments may be converted to a cloud or set ofpoints. By converting the line segments, a desired quantity of pointscorresponding to the interconnected line segments can be selectedmanually or automatically.

At a process 306, the anatomic model, a medical instrument used toperform the medical procedure (e.g., instrument system 200), and thepatient anatomy are co-registered in a common reference frame prior toand/or during the course of an image-guided surgical procedure on thepatient. The common reference frame may be, for example, the surgicalenvironment reference frame or the patient reference frame. The process306 includes localizing the medical instrument with respect to thepatient. The process 306 also includes registering the anatomic modelwith respect to the patient. Generally, registration involves thematching of measured points to points of the model through the use ofrigid and/or non-rigid transforms. Measured points may be generatedusing landmarks in the anatomy, electromagnetic coils scanned andtracked during the procedure, or a shape sensor system. The measuredpoints may be generated for use in an iterative closest point (ICP)technique. ICP and other registration techniques are described in U.S.Provisional Patent Application No. 62/205,440 and U.S. ProvisionalPatent Application No. 62/205,433, both filed Aug. 14, 2015, which areincorporated by reference herein in their entirety. At a process 308,the medical procedure may be performed using the anatomic model data toguide movement of the medical instrument.

Anatomic models created using prior image data, for example CT scans(i.e., computerized tomography scans), are used in an image guidedsurgical procedure to provide the fine anatomic detail suitable for manyprocedures. Models based on prior image data, however, are subject toregistration error and do not illustrate the real-time configuration ofthe anatomy, including any deformation due to cyclical or non-cyclicalanatomic motion, the presence of and tissue deformation due to a medicalinstrument, or other alterations to the patient anatomy that may haveoccurred since the prior image data was obtained. Fluoroscopy is aperspective imaging modality that obtains real-time moving images of apatient anatomy using X-rays. A conventional radiograph is an X-rayimage obtained by placing a part of the patient in front of an X-raydetector and then illuminating it with a short X-ray pulse. In a similarfashion, fluoroscopy uses X-rays to obtain real-time moving images ofthe interior of the patient, including radiopaque medical instruments,radiopaque dye, and/or radiopaque fiducial markers within the surgicalenvironment. Fluoroscopic systems may include C-arm systems whichprovide positional flexibility and are capable of orbital, horizontal,and/or vertical movement via manual or automated control. Non-C-armsystems are stationary and provide less flexibility in movement.Fluoroscopy systems generally use either an image intensifier or aflat-panel detector to generate two dimensional real-time images of apatient anatomy. Bi-planar fluoroscopy systems simultaneously capturetwo fluoroscopic images, each from different (often orthogonal)viewpoints. The quality and utility of X-ray images may vary dependingupon the type of tissue imaged. Denser material such as bone and metalare generally more visible in X-ray images than the air-filled softtissue of the lung. For procedures in the lungs, a CT model providesanatomical detail of airways and tumors that may be hard to discern on afluoroscopy image, but the fluoroscopy image provide real-timevisualization of the medical instrument and dense anatomical tissue.Thus, fluoroscopy images registered with anatomic model may be useful toclinicians navigating certain portions of the anatomy, such as thelungs.

FIG. 5 illustrates an exemplary surgical environment 350 according tosome embodiments, with a surgical coordinate system X_(S), Y_(S), Z_(S),in which a patient P is positioned on a platform 352. The patient P maybe stationary within the surgical environment in the sense that grosspatient movement is limited by sedation, restraint, or other means.Cyclic anatomic motion including respiration and cardiac motion of thepatient P may continue, unless the patient temporarily suspendsrespiratory motion. Within the surgical environment 350, a medicalinstrument 354 is coupled to an instrument carriage 356. The instrumentcarriage 356 is mounted to an insertion stage 358 fixed or movablewithin the surgical environment 350. The instrument carriage 356 may bea component of a teleoperational manipulator assembly (e.g., manipulatorassembly 102) that couples to the instrument 354 to control insertionmotion (i.e. motion in an X_(S) direction) and, optionally, motion of adistal end of the instrument in multiple directions including yaw,pitch, and roll. The instrument carriage 356 or the insertion stage 358may include servomotors (not shown) that control motion of theinstrument carriage along the insertion stage. The medical instrument354 may include a flexible catheter 360 coupled to a proximal rigidinstrument body 362. The rigid instrument body 362 is coupled and fixedrelative to the instrument carriage 356. An optical fiber shape sensor364 extends along the instrument 354 and is operable to measure a shapefrom a fixed or known point 366 to another point such as a portion 368of the catheter 360. In the pictured embodiment, the portion 368 isshown as a distal end portion. In other embodiments, the portion 368 maybe located elsewhere along the length of the catheter 360, including atthe midportion of the catheter. The portion 368 is shaped and configuredsuch that it may serve as an indicator portion of the catheter 360(e.g., the portion 368 may be identified in imaging data). The medicalinstrument 354 may be substantially similar to the medical instrumentsystem 200. A fluoroscopic imaging system 370 (also called a fluoroscopysystem 370) is arranged near the patient P to obtain fluoroscopic imagesof the patient while the catheter 360 is extended within the patient.The system 370 may be, for example a mobile C-arm fluoroscopic imagingsystem. In some embodiments, the system 370 may be a multi-axis ArtisZeego fluoroscopic imaging system from Siemens Corporation ofWashington, D.C.

FIG. 6 is a flowchart illustrating a method 450 for performing imageguided surgery in the surgical environment 350. The methods of thisdescription, including method 450, are illustrated in FIG. 6 as a set ofblocks, steps, operations, or processes. Not all of the illustrated,enumerated operations may be performed in all embodiments of the method450. Additionally, some additional operations that are not expresslyillustrated in the methods may be included before, after, in between, oras part of the enumerated processes. Some embodiments of the methods ofthis description include instructions that corresponded to the processesof the methods as stored in a memory. These instructions may be executedby a processor like a processor of the control system 112.

Thus, some embodiments of the method 450 may begin at a process 452, inwhich prior image data, including pre-operative or intra-operative imagedata, is obtained from imaging technology such as, CT, MRI,thermography, ultrasound, OCT, thermal imaging, impedance imaging, laserimaging, or nanotube X-ray imaging. The prior image data may correspondto two-dimensional, three-dimensional, or four-dimensional (includinge.g., time based or velocity based information) images. As describedabove, an anatomic model is created from the prior image data in ananatomic model reference frame. At a process 454, an instrument sensorreference frame (X_(I), Y_(I), Z_(I)), which can be associated with theshape sensor 222 included in the medical instrument 200, is registeredto the anatomic model reference frame (X_(M), Y_(M), Z_(M)). Thisregistration between the model and instrument frames of reference may beachieved, for example, using a point-based ICP technique as described inincorporated by reference U.S. Provisional Pat. App. Nos. 62/205,440 andNo. 62/205,433. Alternatively, the model reference frame may beregistered to the sensor reference frame or the model and sensorreference frames may be registered to another common reference frame.The common reference frame may be, for example, the surgical environmentreference frame (X_(S), Y_(S), Z_(S)) or a patient reference frame.

At a process 456 and with reference to FIG. 9B, sensor data (as opposedto shape information determined from imaging) is used to calculate poseinformation. For example, in various instances, a sensed position andorientation of a portion of the medical instrument at a location Lwithin, near, adjacent, or outside the patient anatomy is used todetermine the pose information of the medical instrument. The sensedposition and orientation may be obtained, measured, or calculated fromsensor data. In this embodiment, the portion 368 of the medicalinstrument can be referred to as an indicator portion and can comprise aradiopaque distal end portion. In other embodiments, other radiopaqueportions of the medical instrument, which are visible on fluoroscopicimages, may be the indicator portion. The indicator portion can includeany length of the medical instrument which is visible on fluoroscopicimages. The sensor information is received from the optical fiber shapesensor and is used to calculate the sensed position and orientation ofthe indicator portion 368 in the sensor reference frame. Based on theregistration of the instrument sensor reference frame to the anatomicmodel reference frame (or other common reference frame) at process 454,the position and/or orientation (i.e. sensed pose) of the indicatorportion in the sensor frame is translated to the anatomic modelreference frame at a process 458.

At a process 460, the fluoroscopy system 370 captures fluoroscopic imagedata of the patient P and the catheter 360 extended within the patient.One or more of fluoroscopic images, rendered from the fluoroscopic imagedata, is obtained while the indicator portion 368 is positioned at ortouching the anatomic location L. The images obtained while theindicator portion 368 is at the location L may be from a singleviewpoint or may be a multi-planar set of images (including a set ofbi-planar images) showing the indicator portion 368 from multipleviewpoints at the same time and at the same location. In some examples,the catheter 360 can be positioned outside the patient such that theindicator portion 368 is visibly adjacent the anatomic location L withinthe one or more fluoroscopic images.

At a process 462, the indicator portion 368 is identified in thefluoroscopic image data and thus, the position of the location L in thefluoroscopic reference frame is also identified. In various embodiments,the fluoroscopy system 370 is able to generate multi-planar images, thusproviding a three-dimensional fluoroscopic reference frame (X_(F),Y_(F), Z_(F)). The use of multiple images also allows for thedetermination of the orientation of the indicator portion 368, thusproviding pose information for the indicator portion. In otherembodiments, a fluoroscopy system may provide a two-dimensionalfluoroscopic reference frame.

To extract the position of the indicator portion 368 in the fluoroscopicimage and thus the indicated location L in the fluoroscopic referenceframe, various techniques may be used. In one embodiment, with referenceto FIGS. 9A and 9B, the indicator portion 368 may be identified in theimage data by comparing an image 600 in which the indicator portion 368is not present with an image 610 in which the indicator portion 368 ispresent. The two images are analyzed, for example by a computer of thecontrol system 112, to determine the graphical differences between thetwo images. Because the patient anatomy portion of the image is the samein the two images, the catheter 360, including the indicator portion 368is identifiable as the structure unique to image 610. By identifying thegraphical components (e.g. pixels, voxels) associated with theidentified catheter 360, the presence and location of the indicatorportion 368 in the fluoroscopic frame may be calculated. Because theindicator portion 368 is located at the location L, the position of thelocation L is also determined by the graphical analysis that extractsthe indicator portion.

In another embodiment, with reference to FIGS. 9B and 9C, the indicatorportion 368 may be identified in the image data by comparing an image620 in which the indicator portion 368 is at a location K with the image610 in which the indicator portion 368 is at location L. The two imagesare analyzed, for example by a computer of the control system 112, todetermine the graphical differences between the two images. Because thepatient anatomy portion of the image is the same in the two images, thecatheter 360, including the indicator portion 368 is identifiable as thestructure unique in each image 610, 620. By identifying the graphicalcomponents associated with the distal end of the identified catheter360, the presence and location of the indicator portion 368 in thefluoroscopic frame of each image may be calculated. Because theindicator portion 368 is located at the locations L and K, the positionsof locations L and K are also determined by the graphical analysis thatextracts the indicator portion.

In another embodiment, with reference to FIG. 13A, the indicator portion368 may be identified in the image data by a semi-automatic extractiontechnique in which a fluoroscopic image 1000 including an instrument1002 is displayed to a user. The user uses an input device such as atouchscreen, a mouse, a trackball, or eye gaze to create an outline 1004of the instrument 1002 or a portion of the instrument such as the distaltip. Based on the outline 1004 input received from the user, asegmentation algorithm identifies the characteristics (e.g. pixelshading, size) of the instrument 1002 in the image 1000 and proceeds topartition the segments (e.g. pixels or voxels) of the imagecorresponding to the instrument.

In another embodiment, with reference to FIG. 13B, the indicator portion368 may be identified in the image data by a semi-automatic extractiontechnique in which a fluoroscopic image 1010 including an instrument1022 is displayed to a user. A search area 1014 is identified by a useror may be predefined (e.g. the bottom left quadrant of the image) inwhich to search for an entry point 1016 of the medical instrument intothe image. A segmentation algorithm may search for a predetermined shapeassociated with an expected shape of the medical instrument (e.g., anexpected continuity or saturation of shading, an expected width, anexpected length, an expected curvature). After the segmentationalgorithm identifies the medical instrument in the image 1010, thealgorithm proceeds to partition the segments (e.g. pixels or voxels) ofthe image corresponding to the instrument.

In another embodiment, an expected shape is defined by shape informationreceived from a shape sensor and the expected shape is used to identifyan initial search area for use by a semi-automatic extraction technique.The segmentation algorithm may further search for the expected shape inthe initial search area to minimize time and computing resources. Afterthe segmentation algorithm identifies the expected shape, the algorithmproceeds to partition the segments (e.g. pixels or voxels) of the imagecorresponding to the instrument.

In another embodiment, the indicator portion 368 may be identified bygraphically analyzing and recognizing the captured fluoroscopic imagesfor a predetermined (i.e., expected or previously known) radiopaqueshape, such as the shape measured by the shape sensor or by apredetermined (i.e., expected or previously known) shape or marker atthe end of the catheter. For example, a known shape of a needleextending from the catheter or a fixture at the end of the catheter maybe found and extracted from the image. Graphical recognition of theseindicator portions in the fluoroscopic images provides the position ofthe touched location L in the fluoroscopic frame.

Referring again to FIG. 6, at a process 464, the fluoroscopic imagereference frame is registered to the anatomic model reference frame.Alternatively, both the fluoroscopic image reference frame and theanatomic model reference frame are registered to a common referenceframe, such as the surgical reference frame. Because the process 462provides the position and orientation of the indicator portion 368 atlocation L in the fluoroscopic image reference frame and the process 458provides the position and orientation of the indicator portion 368location L in the model reference frame, the respective frame positionsof the indicator portion 368 are correlated to register the framestogether. The processes 456, 458, 460, 462 may be repeated for aplurality of positions of the indicator portion at a plurality oflocations in the patient anatomy. The registration at process 464 may beperformed or enhanced by correlating these multiple locations in therespective frames and performing rigid or non-rigid transformations ofpoints corresponding to the multiple locations.

At a process 466 and with reference to FIGS. 10 and 11, the registeredframes of reference are displayed as the catheter traverses the patientanatomy, allowing the clinician viewing the display image(s) to utilizethe benefits of real-time instrument tracking in the fluoroscopic imageswith the anatomic detail of the prior-time image (e.g., a CT image).FIG. 10 illustrates a display 700 displaying a fluoroscopic image 710having a fluoroscopic reference frame (X_(F), Y_(F), Z_(F)) and aprior-time model image 720 (such as, by way of non-limiting example, aCT image acquired by CT technology or an image acquired by any otherappropriate imaging technology) having model reference frame (X_(M),Y_(M), Z_(M)). The fluoroscopic reference frame and the model referenceframe have been registered and the registered images are displayedside-by-side. With the reference frames registered, structures from oneimage may, optionally, be superimposed or overlaid on the other image toassist a clinician performing a medical procedure. For example, thecatheter 360 visible in the fluoroscopic image 710 may be extracted andoverlaid on the image 720. Additionally or alternatively, target tissue730 (e.g. a tumor) visible in the image 720 may be extracted andoverlaid on the fluoroscopic image 720.

FIG. 11 illustrates a display 800 displaying a single image 810 in whichprior image data 820 has been overlaid on fluoroscopic image data 830.In some embodiments (not shown), a path to target tissue may be plannedwithin the prior-time model image data and displayed within theprior-time model image (e.g., a CT image). The path may then beextracted and overlaid on the fluoroscopic image data.

Optionally, after the fluoroscopic image data is registered to theanatomic model, key features can be viewed and analyzed from twodimensional or three dimensional images generated from the fluoroscopicimage data, the anatomic model, or a combination of the two. Forexample, a shadow in the fluoroscopic image data may indicate a tumor ormay indicate where to look for the tumor in the segmented CT data usedto generate the anatomic model.

Optionally, after the fluoroscopic image data is registered to theanatomic model, virtual fluoroscopic views may be generated. Because theregistration indicates the fluoroscopic image plane relative to themodel, a virtual view of the patient anatomy from another plane of viewmay be generated. For example, a virtual view from a plane orthogonal tothe actual fluoroscopic image plane may be generated from the anatomicmodel to provide the clinician with an experience that approximates abi-plane fluoroscopic image.

Additionally or optionally, with the fluoroscopic view registered to theanatomic model, anatomic features such as target tissue, tumors, orother landmarks may be identified in the fluoroscopic image and used tolocate the corresponding feature in the anatomic model. For example, atumor could be visible in the fluoroscopic view to help identify thecorresponding tumor in the anatomic model. Once identified in theanatomic model, the tumor could be labeled as a target and anavigational path to that target could be planned within the anatomicmodel.

FIG. 7 is a flowchart illustrating another method 500 for performingimage guided surgery in the surgical environment 350. The methods ofthis description, including method 500, are illustrated in FIG. 7 as aset of blocks, steps, operations, or processes. Not all of theillustrated, enumerated operations may be performed in all embodimentsof the method 500. Additionally, some additional operations that are notexpressly illustrated in the methods may be included before, after, inbetween, or as part of the enumerated processes. Some embodiments of themethods of this description include instructions that corresponded tothe processes of the methods as stored in a memory. These instructionsmay be executed by a processor like a processor of the control system112.

Method 500 includes the previously described process 452 of obtainingprior-time imaging data of the patient anatomy, such as a pre-operativeCT scan and the process 454 of registering the instrument sensorreference frame to the anatomic model reference frame. A series ofprocesses 502 describe a subprocess for gathering and matching anatomiclandmark points and registering the fluoroscopic and model referenceframes. At a process 508, the fluoroscopy system 370 capturesfluoroscopic image data of the patient P and the catheter 360 while theindicator portion 368 touches or is positioned adjacent to an anatomicallandmark visible in a fluoroscopic image generated from the image data.The anatomical landmark may be any unique structure visible in thefluoroscopic such as a visible portion of the spine, rib cage, sternum,collar bone, diaphragm, vasculature, or airway tree. At a process 510,the indicator portion 368 is identified in the fluoroscopic image dataand thus, the position of the indicated anatomic landmark in thefluoroscopic reference frame is also identified. In various embodiments,the fluoroscopy system 370 is able to generate multi-planar images, thusproviding a three-dimensional fluoroscopic reference frame (X_(F),Y_(F), Z_(F)). In other embodiments, a fluoroscopy system may provide atwo-dimensional fluoroscopic reference frame. Methods for extracting theindicator portion from the fluoroscopic image data are described above.At a process 512, the same anatomic landmark is selected in anatomicmodel and correlated with the anatomic landmark in the fluoroscopicimage data. For example, while the indicator portion of the cathetertouches the anatomic landmark (as viewed by the clinician in thereal-time fluoroscopic image) a user may touch a touchscreen, displayingthe anatomic model, at the location of the anatomic landmark. Othermarking methods for locating the anatomic landmark in the model may beused. Thus the coordinates of the anatomic landmark in the fluoroscopicreference frame and the coordinates of the anatomic landmark in themodel frame of reference may become correlated. At FIG. 12, acorrelation table 900 can be compiled that references each landmark 910to a position 920 in the fluoroscopic reference frame and to a position930 in the model reference frame. The processes 502 may be repeated foreach of a plurality of anatomic landmarks. For example, three or moreanatomic landmarks may be selected.

At a process 514, the fluoroscopic image reference frame is registeredto the anatomic model reference frame. Anatomic landmark pointregistration is described in incorporated by reference U.S. ProvisionalPat. App. Nos. 62/205,440 and No. 62/205,433. For example, the set offluoroscopic image anatomic reference points are matched with theanatomic landmark point in the model. One or both sets of matched pointsare then rotated, translated or otherwise manipulated by rigid ornon-rigid transforms to register the fluoroscopic and model referenceframes. At a process 516 and with reference to FIGS. 10 and 11, theregistered frames of reference are displayed as the catheter traversesthe patient anatomy, allowing the clinician viewing the display image(s)to utilize the benefits of real-time tracking instrument tracking in thefluoroscopic images with the anatomic detail of the prior-time image(e.g. CT image).

FIG. 8 is a flowchart illustrating a subprocess 550 that may be used inthe method 500 to replace the process 502. At a process 552, thefluoroscopy system 370 captures fluoroscopic image data of the patient Pand the catheter 360 while the indicator portion 368 traverses thepatient anatomic passageways. At a process 554, a plurality of locationpoints of the indicator portion 368 are identified in the fluoroscopicimage data and thus, the positions of the location points in thefluoroscopic reference frame are also identified. In this embodiment,the fluoroscopy system 370 is able to generate multi-planar images from,thus providing a three-dimensional fluoroscopic reference frame (X_(F),Y_(F), Z_(F)). In other embodiments, a fluoroscopy system may provide atwo-dimensional fluoroscopic reference frame. Methods for extracting theindicator portion from the fluoroscopic image data are described above.At a process 556, the fluoroscopic image reference frame is registeredto the anatomic model reference frame. Point cloud registration isdescribed in incorporated by reference U.S. Provisional Pat. App. Nos.62/205,440 and No. 62/205,433. For example, the set of fluoroscopicimage anatomic reference points are rotated, translated or otherwisemanipulated by rigid or non-rigid transforms to match with model pointsin the anatomic model (e.g., model points received from a prior orconcurrent CT scan of the passageways). By ICP or other pointregistration techniques, the fluoroscopic and model reference frames areregistered.

FIG. 14 is a flowchart illustrating a method 1100 for performing imageguided surgery in the surgical environment 350. The method 1100 beginsat a process 1102, in which prior image data, including pre-operative orintra-operative image data, is obtained from imaging technology such as,CT, MRI, thermography, ultrasound, OCT, thermal imaging, impedanceimaging, laser imaging, or nanotube X-ray imaging. The prior image datamay correspond to two-dimensional, three-dimensional, orfour-dimensional (including e.g., time based or velocity basedinformation) images. As described above, an anatomic model is createdfrom the prior image data. At a process 1104, shape sensor informationis received from the medical instrument while the indicator portion ofthe medical instrument is positioned at a location L within the patientanatomy.

At a process 1106, the fluoroscopy system 370 captures fluoroscopicimage data of the patient P and the catheter 360 extended within thepatient. One or more of fluoroscopic images, rendered from thefluoroscopic image data, is obtained while the indicator portion 368 ispositioned at or touching the anatomic location L. The images obtainedwhile the indicator portion 368 is at the location L may be from asingle viewpoint or may be a multi-planar set of images (including a setof bi-planar images) showing the indicator portion 368 from multipleviewpoints at the same time and at the same location.

At a process 1108, the shape of the catheter 360 is identified in thefluoroscopic image data and thus, the position of the location L (at thedistal tip of the catheter) in the fluoroscopic reference frame is alsoidentified. In various embodiments, the fluoroscopy system 370 is ableto generate multi-planar images, thus providing a three-dimensionalfluoroscopic reference frame (X_(F), Y_(F), Z_(F)). In otherembodiments, a fluoroscopy system may provide a two-dimensionalfluoroscopic reference frame. Various embodiments for extracting theshape of the catheter and/or the pose of the indicator portion aredescribed above. At a process 1110, the shape sensor information fromprocess 1110 is compared to the shape information determined from thefluoroscopic image data. If the shape sensor becomes twisted or sharplybent, the shape information determined from an optical fiber shapesensor may contain inaccuracies. Additionally, the error accumulateswith the length of an optical fiber shape sensor, so the shape anddistal tip position may be more inaccurate with longer instruments. Theaccuracy of the sensor information may be improved by fusing theinstrument shape information received from multiple sources. At process1110, the shape sensor information from the medical instrument ismodified based upon the fluoroscopic image shape information. Forexample, the location of the distal tip in the shape sensor informationmay be adjusted to the position of the distal tip in the fluoroscopicimage shape information. In another example, the shape information maybe averaged or modified only along portions (e.g., the distal tipportion) where inaccuracies are expected.

At a process 1112, the modified instrument sensor information isregistered to the anatomic model using any of the registration methodspreviously described. At a process 1114, an image guided medicalprocedure is performed with the medical instrument with the modifiedsensor information providing more accurate localization of theinstrument distal tip. Based on the localized instrument distal tip, avirtual image of the patient anatomy from the perspective (position andorientation) of the distal tip may be generated from the anatomic model.Additionally, based on the localized instrument distal tip, a virtualimage of the medical instrument overlaid on an image from the anatomicmodel may be used to guide movement of the medical instrument.

FIG. 15 illustrates a method 1200 of determining a preferredfluoroscopic plane of view. At a process 1202, prior image data,including pre-operative or intra-operative image data, is obtained fromimaging technology such as, CT, MM, thermography, ultrasound, OCT,thermal imaging, impedance imaging, laser imaging, or nanotube X-rayimaging. The prior image data may correspond to two-dimensional,three-dimensional, or four-dimensional (including e.g., time based orvelocity based information) images. As described above, an anatomicmodel is created from the prior image data. At a process 1204, theinstrument sensor 222 of medical instrument 200 is registered to theanatomic model as described above for method 450 at process 454. At aprocess 1206, a preferred fluoroscopic plane of view is determined toallow the clinician to visualize movement of distal tip of the catheter,movement of a biopsy needle or other tool emerging from the distal tipof the catheter, and/or a tissue area to be engaged by the tool (e.g., atumor) or to be avoided by the tool (e.g., a lung pleura to avoidperforation). More specifically, the preferred fluoroscopic plane may beselected by determining the pose of the distal tip portion of theinstrument from the shape sensor information. The preferred fluoroscopicplane may be generally parallel to the pose of the distal tip portion ofthe instrument (e.g., the plane of view of FIG. 13B). Additionally oralternatively, the preferred fluoroscopic plane may be determined bymeasuring a distance between the distal tip portion of the instrumentand a tissue area of interest and determining the fluoroscopic plane ofview that provides the greatest distance. This fluoroscopic plane ofview may be generally parallel to the trajectory between the distal tipportion of the instrument and the tissue area, thus providing the mostaccurate information to clinician about whether a biopsy needle hasintercepted the target tissue area or has avoided an area that wouldcause injury to the patient.

FIG. 16 illustrates a method 1300 for driving a medical instrument undertwo-dimensional fluoroscopic guidance. At a process 1302, fluoroscopicimage data of a patient anatomy in a surgical reference frame isobtained from a fluoroscopy system 370. The orientation of thefluoroscopy system and thus the orientation of the plane of imaging maybe determined via a variety of methods including the use of externaltracking systems, imaged fiducials, or use of shape sensing data asdescribed above for method 450. A description of the determination ofthe fluoroscopic plane of imaging is found in U.S. ProvisionalApplication No. 62/216,494, covering Systems and Methods of PoseEstimation and Calibration of Perspective Imaging System in Image GuidedSurgery, filed Sep. 10, 2015 which is incorporated herein by referencein its entirety. In some instances, a graphical rendering of thefluoroscopy system may be generated to facilitate obtaining afluoroscopic image in the desired fluoroscopic image plane. Inparticular, such a rendering may assist the user in positioning elementsof the fluoroscopy system (e.g., the fluoro arm or X-ray imager) toappropriately capture fluoroscopic images in the desired orpredetermined fluoroscopic plane. In some instances, the system or usermay receive a set of joint configurations for a fluoroscopy system tobetter achieve a system configuration for obtaining a fluoroscopic imagein the desired or predetermined fluoroscopic image plane. At a process1304, a two-dimensional fluoroscopic image is generated for display fromthe fluoroscopic image data. The displayed image has a plane oforientation based on the plane of orientation of the plane of imaging.At a process 1306, the control system 112 receives a command to drivemovement of the catheter system 202. At a process 1308, the motion ofthe catheter system 202 or a portion of the catheter is constrained tothe plane of plane of orientation of the displayed fluoroscopic image.In one embodiment, only the motion of the indicator portion of thecatheter may be constrained to the plane of orientation of thefluoroscopic image. The motion of the indicator portion of the cathetermay be constrained by limiting movement of the operator controls in ateleoperational system so that the operator is prevented from moving thecontrols in a direction that would move the portion of the catheter outof the plane of constraint. Additionally or alternatively, the motion ofthe indicator portion of the catheter may be constrained by restrictingthe movement of at least one actuator or actuation cable in ateleoperational manipulator assembly. Despite the constraints on theoperator controls or the actuation mechanism of the instrument in theabove described open loop constraint system, the indicator portion ofthe catheter may still experience movement of out the constrained planedue to anatomical forces from adjacent tissue. In a closed loop system,sensor information received from shape, position, or other sensors ofthe medical instrument may be received and analyzed by the controlsystem to recognize movement of the indicator portion out of the planeof orientation of the fluoroscopic image. Responsive to the recognizedout-of-plane movement, the control system may provide a signal or acommand to adjust the indicator portion back into the plane oforientation. In some instances, the signal and/or command to adjust theindicator portion may be overridden or ignored. In other instances, thesignal and/or command to adjust the indicator portion may automaticallyadjust the indicator portion back into the plane of orientation. Invarious embodiments, one or more additional fluoroscopic images may beobtained from an orthogonal or other non-parallel plane to the plane ofconstraint, allowing the clinician to observe any movement of theindicator portion out of the plane of constraint. In variousembodiments, constraining motion of the indicator portion to the planeof orientation of the displayed fluoroscopic image may be initiated byactuation of an operator control switch which may include a manualswitch, a voice-activated switch, a foot-activated switch, or otheroperator control mechanism. Additionally or alternatively, constrainingmotion of the indicator portion to the plane of orientation of thedisplayed fluoroscopic image may be initiated by the control system 112in response to the display of the fluoroscopic image or recognition thatthe operator is viewing the fluoroscopic image.

Although this disclosure describes various systems and methods forteleoperated systems, they are also contemplated for use innon-teleoperated systems where manipulator assemblies and instrumentsare directly controlled. Although various provided examples describe theuse of procedures performed within the anatomy, in alternativeembodiments, the apparatus and methods of this disclosure need not beused within the anatomy but rather may also be used outside of thepatient anatomy.

One or more elements in embodiments of the invention may be implementedin software to execute on a processor of a computer system such ascontrol system 112. When implemented in software, the elements of theembodiments of the invention are essentially the code segments toperform the necessary tasks. The program or code segments can be storedin a non-transitory processor readable storage medium or device,including any medium that can store information including an opticalmedium, semiconductor medium, and magnetic medium. Processor readablestorage device examples include an electronic circuit; a semiconductordevice, a semiconductor memory device, a read only memory (ROM), a flashmemory, an erasable programmable read only memory (EPROM); a floppydiskette, a CD-ROM, an optical disk, a hard disk, or other storagedevice, The code segments may be downloaded via computer networks suchas the Internet, Intranet, etc.

Note that the processes and displays presented may not inherently berelated to any particular computer or other apparatus. The requiredstructure for a variety of these systems will appear as elements in theclaims. In addition, the embodiments of the invention are not describedwith reference to any particular programming language. It will beappreciated that a variety of programming languages may be used toimplement the teachings of the invention as described herein.

While certain exemplary embodiments of the invention have been describedand shown in the accompanying drawings, it is to be understood that suchembodiments are merely illustrative of and not restrictive on the broadinvention, and that the embodiments of the invention not be limited tothe specific constructions and arrangements shown and described, sincevarious other modifications may occur to those ordinarily skilled in theart.

1. A method performed by a computing system comprising: receiving afluoroscopic image of a patient anatomy while a portion of a medicalinstrument is positioned within the patient anatomy, the fluoroscopicimage having a fluoroscopic frame of reference, wherein the portion hasa sensed position in an anatomic model frame of reference; identifyingthe portion in the fluoroscopic image; identifying an extracted positionof the portion in the fluoroscopic frame of reference using theidentified portion in the fluoroscopic image; and registering thefluoroscopic frame of reference to the anatomic model frame of referencebased on the sensed position of the portion and the extracted positionof the portion.
 2. The method of claim 1, further comprising:identifying an extracted orientation of the portion in the fluoroscopicframe of reference using the identified portion in the fluoroscopicimage, wherein the portion has a sensed orientation in the anatomicmodel frame of reference, and wherein registering the fluoroscopic frameof reference to the anatomic model frame of reference is further basedon the sensed orientation of the portion and the extracted orientationof the portion.
 3. The method of claim 1, wherein identifying theportion in the fluoroscopic image includes identifying an expected shapeof the portion in the fluoroscopic image.
 4. The method of claim 1,wherein identifying the portion in the fluoroscopic image includescomparing the fluoroscopic image of the patient anatomy while theportion of the medical instrument is positioned within the patientanatomy to a fluoroscopic image of the patient anatomy recorded when theportion of the medical instrument is not positioned within the patientanatomy.
 5. The method of claim 1, wherein identifying the portion inthe fluoroscopic image includes comparing the fluoroscopic image of thepatient anatomy while the portion of the medical instrument ispositioned at a first location within the patient anatomy to afluoroscopic image of the patient anatomy recorded when the portion ofthe medical instrument is positioned at a second location within thepatient anatomy.
 6. The method of claim 5, further comprising receivinga set of model points for an anatomic model of passageways of thepatient anatomy in the anatomic model frame of reference.
 7. The methodof claim 6, wherein the set of model points for an anatomic model ofpassageways is developed from a computerized tomography scan.
 8. Themethod of claim 6, further comprising displaying the portion of themedical instrument within a co-registered image of a portion of thefluoroscopic image and a portion of the anatomic model.
 9. The method ofclaim 8, further comprising: identifying and displaying a target tissuewithin the anatomic model; and overlaying the target tissue in theco-registered image of the portion of the fluoroscopic image.
 10. Themethod of claim 9, further comprising: planning a path to the targettissue in the anatomic model; and overlaying the path in theco-registered image of the portion of the fluoroscopic image.
 11. Themethod of claim 1, further comprising: receiving sensor positioninformation from a position sensor of the medical instrument todetermine the sensed position of the portion of the medical instrument,wherein the sensor position information is in a sensor frame ofreference; registering the anatomic model frame of reference and thesensor frame of reference, wherein the anatomic model frame of referenceis associated with an anatomic model of anatomic passageways of thepatient anatomy; and determining, from the registration of the anatomicmodel frame of reference and the sensor frame of reference, the sensedposition of the portion in the anatomic model frame of reference. 12.The method of claim 11, wherein the position sensor is an optical fibershape sensor extending along the medical instrument.
 13. The method ofclaim 11, wherein determining the sensed position of the portion of themedical instrument in the anatomic model frame of reference includesreferencing a set of coordinates of the sensor position information inthe sensor frame of reference with a corresponding set of coordinates inthe anatomic model frame of reference.
 14. The method of claim 11,wherein registering the anatomic model frame of reference and the sensorframe of reference includes: receiving a set of model points of theanatomic model; receiving a set of measured points collected from withinthe anatomic passageways, each point comprising coordinates within thesensor frame of reference; matching measured points of the set ofmeasured points to model points of the set of model points to generate aset of matches; and moving the set of measured points relative to theset of model points based upon the set of matches.
 15. A methodperformed by a computing system comprising: identifying a set ofpositions of a plurality of anatomic landmarks, the plurality ofanatomic landmarks rendered in an anatomic model of passageways of apatient anatomy in a model frame of reference; receiving fluoroscopicimage data of the patient anatomy while a portion of a medicalinstrument traverses the plurality of anatomic landmarks in thepassageways of the patient anatomy, the fluoroscopic image data having afluoroscopic frame of reference; identifying a set of positions of theportion of the medical instrument at the plurality of anatomic landmarksin the fluoroscopic frame of reference; and registering the set ofpositions of the plurality of anatomic landmarks in the model frame ofreference and the set of positions of the portion of the medicalinstrument at the plurality of anatomic landmarks in the fluoroscopicframe of reference to a common frame of reference.
 16. The method ofclaim 15, wherein identifying the set of positions of the portion of themedical instrument in the fluoroscopic frame of reference includesidentifying a predetermined shape of the portion of the medicalinstrument in the fluoroscopic frame of reference.
 17. The method ofclaim 15, wherein identifying the set of positions of the portion of themedical instrument in the fluoroscopic frame of reference includescomparing the fluoroscopic image data of the patient anatomy while theportion of the medical instrument is positioned at least one of theplurality of landmarks to fluoroscopic image data of the patient anatomyrecorded when the portion of the medical instrument is not positionedwithin the patient anatomy.
 18. The method of claim 15, whereinidentifying the set of positions in the fluoroscopic frame of referenceincludes comparing the fluoroscopic image data of the patient anatomywhile the portion of the medical instrument is positioned at least oneof the plurality of landmarks to an image of the patient anatomyrecorded when the portion of the medical instrument is positioned atanother location within the patient anatomy.
 19. The method of claim 15,further comprising displaying a co-registered image of a portion of thefluoroscopic image, a portion of the anatomic model, and the portion ofthe medical instrument.
 20. The method of claim 15, wherein the commonframe of reference is the model frame of reference or is thefluoroscopic frame of reference. 21-41. (canceled)